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4.6.7. mysqlbinlog — Utility for Processing Binary Log Files

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4.6.7.1. mysqlbinlog Hex Dump Format
4.6.7.2. mysqlbinlog Row Event Display

The server's binary log consists of files containing “events” that describe modifications to database contents. The server writes these files in binary format. To display their contents in text format, use the mysqlbinlog utility. You can also use mysqlbinlog to display the contents of relay log files written by a slave server in a replication setup because relay logs have the same format as binary logs. The binary log and relay log are discussed further in Section 5.2.4, “The Binary Log”, and Section 16.4.2, “Replication Relay and Status Files”.

Invoke mysqlbinlog like this:

shell> mysqlbinlog [options] log_file ...

For example, to display the contents of the binary log file named binlog.000003, use this command:

shell> mysqlbinlog binlog.0000003

The output includes events contained in binlog.000003. Event information includes the statement, the ID of the server on which it was executed, the timestamp when the statement was executed, how much time it took, and so forth.

The output from mysqlbinlog can be re-executed (for example, by using it as input to mysql) to reapply the statements in the log. This is useful for recovery operations after a server crash. For other usage examples, see the discussion later in this section.

Normally, you use mysqlbinlog to read binary log files directly and apply them to the local MySQL server. It is also possible to read binary logs from a remote server by using the --read-from-remote-server option. When you read remote binary logs, the connection parameter options can be given to indicate how to connect to the server. These options are --host, --password, --port, --protocol, --socket, and --user; they are ignored except when you also use the --read-from-remote-server option.

mysqlbinlog supports the following options. It also reads option files and supports the options for processing them described at Section 4.2.3.3.1, “Command-Line Options that Affect Option-File Handling”.

Table 4.11. mysqlbinlog Options

Format	Config File	Description	Introduction
--base64-output[=value]	base64-output	Print binary log entries using base-64 encoding	5.1.5
--character-sets-dir=path	character-sets-dir	The directory where character sets are installed
--database=db_name	database	List entries for just this database
--debug[=debug_options]	debug	Write a debugging log
--debug-check	debug-check	Print debugging information when the program exits	5.1.21
--debug-info	debug-info	Print debugging information, memory and CPU statistics when the program exits	5.1.21
--disable-log-bin	disable-log-bin	Disable binary logging
--force-read	force-read	If mysqlbinlog reads a binary log event that it does not recognize, it prints a warning
--help		Display help message and exit
--hexdump	hexdump	Display a hex dump of the log in comments	5.1.2
--host=host_name	host	Connect to the MySQL server on the given host
--local-load=path	local-load	Prepare local temporary files for LOAD DATA INFILE in the specified directory
--offset=#	offset	Skip the first N entries in the log
--password[=password]	password	The password to use when connecting to the server
--port=port_num	port	The TCP/IP port number to use for the connection
--protocol=type	protocol	The connection protocol to use
--read-from-remote-server	read-from-remote-server	Read the binary log from a MySQL server rather than reading a local log file
--result-file=name	result-file	Direct output to the given file
--server-id=id	server-id	Extract only those events created by the server having the given server ID	5.1.4
--set-charset=charset_name	set-charset	Add a SET NAMES charset_name statement to the output	5.1.12
--short-form	short-form	Display only the statements contained in the log
--socket=path	socket	For connections to localhost
--start-datetime=datetime	start-datetime	Start reading the binary log at the first event having a timestamp equal to or later than the datetime argument
--start-position=#	start-position	Start reading the binary log at the first event having a position equal to or greater than the argument
--stop-datetime=datetime	stop-datetime	Stop reading the binary log at the first event having a timestamp equal to or greater than the datetime argument
--stop-position=#	stop-position	Stop reading the binary log at the first event having a position equal to or greater than the argument
--to-last-log	to-last-log	Do not stop at the end of the requested binary log from a MySQL server, but rather continue printing until the end of the last binary log
--user=user_name,	user	The MySQL user name to use when connecting to the server
--verbose		Reconstruct row events as SQL statements	5.1.28
--version		Display version information and exit
--write-binlog	write-binlog	Log ANALYZE, OPTIMIZE, REPAIR statements to binary log. --skip-write-binlog adds NO_WRITE_TO_BINLOG to these statements.	5.1.18

--help, -?

Display a help message and exit.
--base64-output[=value]

This option determines when events should be displayed encoded as base-64 strings using BINLOG statements. The option has these allowable values (not case sensitive):
- AUTO ("automatic") or UNSPEC ("unspecified") displays BINLOG statements automatically when necessary (that is, for format description events and row events). This is the default if no --base64-output option is given.
  
  Note
  
  Automatic BINLOG display is the only safe behavior if you intend to use the output of mysqlbinlog to re-execute binary log file contents. The other option values are intended only for debugging or testing purposes because they may produce output that does not include all events in executable form.
- ALWAYS displays BINLOG statements whenever possible. This is the implied value if the option is given as --base64-output without a value.
- NEVER causes BINLOG statements not to be displayed. mysqlbinlog exits with an error if a row event is found that must be displayed using BINLOG.
- DECODE-ROWS specifies to mysqlbinlog that you intend for row events to be decoded and displayed as commented SQL statements by also specifying the --verbose option. Like NEVER, DECODE-ROWS suppresses display of BINLOG statements, but unlike NEVER, it does not exit with an error if a row event is found.
The --base64-output option was introduced in MySQL 5.1.5, to be given as --base64-output or --skip-base64-output (with the sense of AUTO or NEVER). The option values described in the preceding list may be used as of MySQL 5.1.24, with the exception of UNSPEC and DECODE-ROWS, which are available as of MySQL 5.1.28.

For examples that show the effect of --base64-output and --verbose on row event output, see Section 4.6.7.2, “mysqlbinlog Row Event Display”.
--character-sets-dir=path

The directory where character sets are installed. See Section 9.2, “The Character Set Used for Data and Sorting”.
--database=db_name, -d db_name

List entries for just this database (local log only). You can only specify one database with this option - if you specify multiple --database options, only the last one is used. This option forces mysqlbinlog to output entries from the binary log where the default database (that is, the one selected by USE) is db_name. Note that this does not replicate cross-database statements such as UPDATE some_db.some_table SET foo='bar' while having selected a different database or no database.

Note

This option did not work correctly for mysqlbinlog with row-based logging prior to MySQL 5.1.37. (Bug#42941)
--debug[=debug_options], -# [debug_options]

Write a debugging log. A typical debug_options string is 'd:t:o,file_name'. The default is 'd:t:o,/tmp/mysqlbinlog.trace'.
--debug-check

Print some debugging information when the program exits. This option was added in MySQL 5.1.21.
--debug-info

Print debugging information and memory and CPU usage statistics when the program exits. This option was added in MySQL 5.1.21.
--disable-log-bin, -D

Disable binary logging. This is useful for avoiding an endless loop if you use the --to-last-log option and are sending the output to the same MySQL server. This option also is useful when restoring after a crash to avoid duplication of the statements you have logged.

This option requires that you have the SUPER privilege. It causes mysqlbinlog to include a SET sql_log_bin = 0 statement in its output to disable binary logging of the remaining output. The SET statement is ineffective unless you have the SUPER privilege.
--force-read, -f

With this option, if mysqlbinlog reads a binary log event that it does not recognize, it prints a warning, ignores the event, and continues. Without this option, mysqlbinlog stops if it reads such an event.
--hexdump, -H

Display a hex dump of the log in comments, as described in Section 4.6.7.1, “mysqlbinlog Hex Dump Format”. This output can be helpful for replication debugging. This option was added in MySQL 5.1.2.
--host=host_name, -h host_name

Get the binary log from the MySQL server on the given host.
--local-load=path, -l path

Prepare local temporary files for LOAD DATA INFILE in the specified directory.
--offset=N, -o N

Skip the first N entries in the log.
--password[=password], -p[password]

The password to use when connecting to the server. If you use the short option form (-p), you cannot have a space between the option and the password. If you omit the password value following the --password or -p option on the command line, you are prompted for one.

Specifying a password on the command line should be considered insecure. See Section 5.5.6.2, “End-User Guidelines for Password Security”.
--port=port_num, -P port_num

The TCP/IP port number to use for connecting to a remote server.
--position=N, -j N

Deprecated. Use --start-position instead.
--protocol={TCP|SOCKET|PIPE|MEMORY}

The connection protocol to use for connecting to the server. It is useful when the other connection parameters normally would cause a protocol to be used other than the one you want. For details on the allowable values, see Section 4.2.2, “Connecting to the MySQL Server”.
--read-from-remote-server, -R

Read the binary log from a MySQL server rather than reading a local log file. Any connection parameter options are ignored unless this option is given as well. These options are --host, --password, --port, --protocol, --socket, and --user.

This option requires that the remote server be running. It works only for binary log files on the remote server, not relay log files.
--result-file=name, -r name

Direct output to the given file.
--server-id=id

Extract only those events created by the server having the given server ID. This option is available as of MySQL 5.1.4.
--set-charset=charset_name

Add a SET NAMES charset_name statement to the output to specify the character set to be used for processing log files. This option was added in MySQL 5.1.12.
--short-form, -s

Display only the statements contained in the log, without any extra information.
--socket=path, -S path

For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.
--start-datetime=datetime

Start reading the binary log at the first event having a timestamp equal to or later than the datetime argument. The datetime value is relative to the local time zone on the machine where you run mysqlbinlog. The value should be in a format accepted for the DATETIME or TIMESTAMP data types. For example:
```
shell> mysqlbinlog --start-datetime="2005-12-25 11:25:56" binlog.000003
```
This option is useful for point-in-time recovery. See Section 6.2, “Example Backup and Recovery Strategy”.
--start-position=N

Start reading the binary log at the first event having a position equal to or greater than N. This option applies to the first log file named on the command line.
--stop-datetime=datetime

Stop reading the binary log at the first event having a timestamp equal to or later than the datetime argument. This option is useful for point-in-time recovery. See the description of the --start-datetime option for information about the datetime value.
--stop-position=N

Stop reading the binary log at the first event having a position equal to or greater than N. This option applies to the last log file named on the command line.
--to-last-log, -t

Do not stop at the end of the requested binary log from a MySQL server, but rather continue printing until the end of the last binary log. If you send the output to the same MySQL server, this may lead to an endless loop. This option requires --read-from-remote-server.
--user=user_name, -u user_name

The MySQL user name to use when connecting to a remote server.
--verbose, -v

Reconstruct row events and display them as commented SQL statements. If given twice, the output includes comments to indicate column data types and some metadata. This option was added in MySQL 5.1.28.

For examples that show the effect of --base64-output and --verbose on row event output, see Section 4.6.7.2, “mysqlbinlog Row Event Display”.
--version, -V

Display version information and exit.
--write-binlog

This option is enabled by default, so that ANALYZE TABLE, OPTIMIZE TABLE, and REPAIR TABLE statements generated by mysqlcheck are written to the binary log. Use --skip-write-binlog to cause NO_WRITE_TO_BINLOG to be added to the statements so that they are not logged. Use the --skip-write-binlog when these statements should not be sent to replication slaves or run when using the binary logs for recovery from backup. This option was added in MySQL 5.1.18.

You can also set the following variable by using --var_name=value syntax:

open_files_limit

Specify the number of open file descriptors to reserve.

You can pipe the output of mysqlbinlog into the mysql client to execute the statements contained in the binary log. This is used to recover from a crash when you have an old backup (see Section 6.1, “Database Backups”). For example:

shell> mysqlbinlog binlog.000001 | mysql

Or:

shell> mysqlbinlog binlog.[0-9]* | mysql

You can also redirect the output of mysqlbinlog to a text file instead, if you need to modify the statement log first (for example, to remove statements that you do not want to execute for some reason). After editing the file, execute the statements that it contains by using it as input to the mysql program.

mysqlbinlog has the --start-position option, which prints only those statements with an offset in the binary log greater than or equal to a given position (the given position must match the start of one event). It also has options to stop and start when it sees an event with a given date and time. This enables you to perform point-in-time recovery using the --stop-datetime option (to be able to say, for example, “roll forward my databases to how they were today at 10:30 a.m.”).

If you have more than one binary log to execute on the MySQL server, the safe method is to process them all using a single connection to the server. Here is an example that demonstrates what may be unsafe:

shell> mysqlbinlog binlog.000001 | mysql # DANGER!!
shell> mysqlbinlog binlog.000002 | mysql # DANGER!!

Processing binary logs this way using different connections to the server causes problems if the first log file contains a CREATE TEMPORARY TABLE statement and the second log contains a statement that uses the temporary table. When the first mysql process terminates, the server drops the temporary table. When the second mysql process attempts to use the table, the server reports “unknown table.”

To avoid problems like this, use a single connection to execute the contents of all binary logs that you want to process. Here is one way to do so:

shell> mysqlbinlog binlog.000001 binlog.000002 | mysql

Another approach is to write all the logs to a single file and then process the file:

shell> mysqlbinlog binlog.000001 >  /tmp/statements.sql
shell> mysqlbinlog binlog.000002 >> /tmp/statements.sql
shell> mysql -e "source /tmp/statements.sql"

mysqlbinlog can produce output that reproduces a LOAD DATA INFILE operation without the original data file. mysqlbinlog copies the data to a temporary file and writes a LOAD DATA LOCAL INFILE statement that refers to the file. The default location of the directory where these files are written is system-specific. To specify a directory explicitly, use the --local-load option.

Because mysqlbinlog converts LOAD DATA INFILE statements to LOAD DATA LOCAL INFILE statements (that is, it adds LOCAL), both the client and the server that you use to process the statements must be configured to allow LOCAL capability. See Section 5.3.4, “Security Issues with LOAD DATA LOCAL”.

MySQL Enterprise. For expert advice on the security implications of enabling LOCAL, subscribe to the MySQL Enterprise Monitor. For more information, see http://www.mysql.com/products/enterprise/advisors.html.

Warning

The temporary files created for LOAD DATA LOCAL statements are not automatically deleted because they are needed until you actually execute those statements. You should delete the temporary files yourself after you no longer need the statement log. The files can be found in the temporary file directory and have names like original_file_name-#-#.

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User Comments

Posted by Tom Mulkins on September 23 2003 12:31pm

[Delete] [Edit]

I had some problems using mysqlbinlog with temporary files. It would have helped to have an explanation above but here is a brief example:

mysqlbinlog -d mydb -r mydb.sql mydb-bin.001

/*The above command will create a file called mydb.sql in my CWD(current working directory) with queries extracted from binary log mydb-bin.001 for mydb database queries only*/

Now say I had some load data infile statements in my binary log. If my /tmp directory did not contain those files mysqbinlog would create them for me. Here's th problem, if the file aready exists mysqlbinlog will error out with message File: 'tmp/XXX.csv' not found. Yet if you look in your /tmp directory there it is! Don't panic...mysqlbinlog won't write over an existing file and there is no flag to do so (in my opinion there should be that option).

Now you could delete the files from your /tmp directory and et mysqlbinlog recreate them for you but it is simpler to create a tmp directory in your CWD like this:

mkdir tmp

Now use the mysqlbinlog flag --local-load to specify your CWD/tmp directory to WRITE the files like this:

mysqlbinlog -d mydb -r mydb.sql --local-load="tmp/" mydb-bin.001

Your files will be created in CWD/tmp. Should you need to run the mysqlbinlog utilty again just rm CWD/tmp/* and run the utility again.

Hope this helps,
Tom

Posted by KEvin on February 9 2005 2:06pm

[Delete] [Edit]

Some things to know about mysqlbinlog which did not strike me as obvious (also it is hinted by the doc) :

--read-from-remote-server :
1) with this option you can only read files present in binary_log-bin.index on the master so you cannot read relay log files on the distant server
2) the distant mysql server must be up (you cannot just read the distant files), so it loses much of its utility : if the distant master is up you can "start slave" or "change master to MASTER_LOG_FILE=...".
But if the master is down and you want to get the latest changes you must copy the remote (with scp for example) binary logs and then run mysqlbinlog locally ...

--start-position (or --position) :
1) it must be the exact position of an event.
2) it is the first position that will be read so you must not use the "Read_Master_Log_Pos" (as shown by "show slave status") which is the position of the last event done.
You have to use :
--start-position=Read_Master_Log_Pos --offset=1 Master_Log_File
to skip the first event.
As Read_Master_Log_Pos is one of the most easy position to get it is a pity that you have to specify the offset each time...

Posted by john danilson on September 8 2006 6:40pm

[Delete] [Edit]

I found the --start-datetime and --stop-datetime to be finicky about the format. While yyyy-mm-dd hh:mm:ss work fine elsewhere, this expected yy-mm-dd hh:mm:ss to work.

Posted by Yiannis Mavridis on April 30 2007 9:24am

[Delete] [Edit]

Regarding KEvin
--start-position (or --position) :
1) it must be the exact position of an event.
2) it is the first position that will be read so you must not use the "Read_Master_Log_Pos" (as shown by "show slave status") which is the position of the last event done.
You have to use :
--start-position=Read_Master_Log_Pos --offset=1 Master_Log_File
to skip the first event.
As Read_Master_Log_Pos is one of the most easy position to get it is a pity that you have to specify the offset each time...

I tested and i found that you do not need to use the offset=1 like KEvin is saying above, because the exec_master_log_pos on the 'show slave status' view contains the next not yet executed command of the binlog

Posted by Baron Schwartz on December 13 2007 2:40pm

[Delete] [Edit]

On Linux, you can use -l /dev/null to avoid the temp files if you're just looking through the output. mysqlbinlog will complain, but it won't create the file and it won't create the corresponding LOAD DATA INFILE statement (because it couldn't create the file).

This is useful if your log files have a lot of very large LOAD DATA INFILE statements, and you don't want to incur the overhead of writing them to disk and then deleting them.

Posted by Jason Ho on August 19 2008 1:49am

[Delete] [Edit]

If the sql generated by mysqlbinlog is not processed by mysql, this could be the root cause:

http://bugs.mysql.com/bug.php?id=34541
(And that you have configured your server to execute "set autocommit=0" on client connect.)

An indication is that the mysql client complains on this line:

SET /*!*/;

A workaround would be replacing the bad line:

mysqlbinlog mysql-bin.000011 | sed -e 's/SET \/\*\!\*\//SET AUTOCOMMIT=0/g' | mysql

Posted by Jim Grill on September 19 2008 2:33pm

[Delete] [Edit]

This may seem obvious but I had to help someone with this...

If you use the --start-datetime= option and you have a large binlog, be patient. It may take a while to return results. Don't hit control+c thinking it's broken or something. Just wait patiently for what you're looking for to be found.

Posted by Phillip Gee on March 11 2009 10:50am

[Delete] [Edit]

Yiannis Mavridis is right.

Don't listen to KEvin and use the --offset=1 switch, it will miss the first command. If there's only been one command since the downtime then you won't be updating your slave.

Caused me a world of pain listening to this while testing.

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4.6.7. mysqlbinlog — Utility for Processing Binary Log Files

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